Braids, Conformal Module and Entropy
I will discuss two invariants of conjugacy classes of braids and some of their applications. The first invariant is the conformal module which implicitly occurred already in a paper of Gorin and Lin in connection with their interest in the 13. Hilbert problem. The second is a popular dynamical invariant, the entropy. It occurred in connection with Thurston's theory of surface homeomorphisms. It turns out that these invariants are related: They are inverse proportional.